PET/MR in Assessing Response to Neoadjuvant Radiation Therapy in the Tx of High Grade Sarcomas

Investigators propose that a PET/MR study at the midpoint of radiation treatment will
accurately predict which patients will respond to neoadjuvant radiation therapy. The study
will enroll patients with high-grade sarcomas as identified by preoperative biopsy that will
be treated with neoadjuvant radiation into the study. The standard of care for these patients
is to receive MRI scans at pre-treatment and post-treatment time points. Patients in this
study will receive their standard pre- and post-treatment imaging in the form of PET/MR, with
PET conducted simultaneously with MRI, and within the context of the study they will also
receive one additional PET/MR at the end of the second week of therapy. These patients will
then receive curative intent surgery and be followed in the usual fashion and assessed for
local and/or distant recurrent disease. The pathology will be assessed for completeness of
resection and percent of necrosis. On the basis of pathology, patients will be classified as
responsive or non-responsive to therapy. Quantitative measures from PET and MRI will be
computed: the change in PET tumor-mean standardized uptake value (SUV) and tumor size as
assessed by MRI, from pre- to post-treatment, and from pre- to mid-treatment. The image-based
quantitative measures will be correlated with the pathology outcomes to evaluate
predictability of the image measures for treatment response. Patients will be followed with
the intent of further correlating image measures with clinical outcomes.

Inclusion Criteria:

- Age ≥ 18 years of age (no upper age limit)

- Signed, IRB-approved written informed consent

- Must have a biopsy-proven high-grade retroperitoneal or soft tissue extremity sarcoma
confirmed by independent evaluation of a UNC sarcoma specialized pathologist.

- Must have surgically curable disease as evaluated by initial imaging by our UNC
surgeons.

- Must be in acceptable health to undergo radiation therapy and curative intent surgery
as assessed by UNC surgeons and radiation oncologist.

- Must be able to understand and comply with study procedures for the entire length of
the study.

- Must receive their neoadjuvant radiation therapy and curative intent surgery at UNC
Hospitals - Chapel Hill location.

- Women of childbearing potential must have a negative serum or urine pregnancy test
performed within 7 days prior to each PET/MRI

Exclusion Criteria:

- Inability to tolerate MRI (e.g., inability to lie flat for >1 hour)

- Presence of pacemaker, intracranial aneurysm clip, bladder stimulator, cochlear
implant or metal near eyes or near pelvis that would create excessive imaging artifact

- Poorly controlled diabetes mellitus

- Creatinine > 1.8 mg/dL OR GFR < 30mL/min

- Body Mass Index (BMI) > 35

- Active vaginal bleeding requiring packing and emergent radiation therapy

- Pregnancy or lactating female

- History of a prior malignancy within past 5 years are excluded unless they have been
disease free for 3 or more years

- Substance abuse, medical, psychological, or social conditions that may interfere with
the patient's participation in the study

- Evidence of distant disease on physical exam or initial imaging

- Medical conditions precluding radiation therapy or curative intent surgery

- Previous radiation exposure precluding radiation therapy

- Had serious reaction to contrast agent

- Incarcerated or otherwise institutionalized at time of enrollment